Tiêu chuẩn ASTM a335 a335m 02 ;QTMZNS9BMZM1TS1SRUQ

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
An American National Standard

Designation: A 335/A 335M – 023

Standard Specification for

Seamless Ferritic Alloy-Steel Pipe for High-Temperature
Service1
This standard is issued under the fixed designation A 335/A 335M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.

1
This specification is under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.10
on Stainless and Alloy Steel Tubular Products.
Current edition approved Sept. Apr. 10, 20023. Published October 2002. May 2003. Originally published as A 335 – 51 T. approved in 1951. Last previous edition approved
in 2002 as A 335/A 335M – -012.

Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.

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A 335/A 335M – 023
1. Scope *
1.1 This specification2 covers nominal wall and minimum wall seamless ferritic alloy-steel pipe intended for high-temperature
service. Pipe ordered to this specification shall be suitable for bending, flanging (vanstoning), and similar forming operations, and

for fusion welding. Selection will depend upon design, service conditions, mechanical properties, and high-temperature
characteristics.
1.2 Several grades of ferritic steels (see Note 1) are covered. Their compositions are given in Table 1.
NOTE 1—Ferritic steels in this specification are defined as low- and intermediate-alloy steels containing up to and including 10 % chromium.

1.3 Supplementary requirements (S1 to S7) of an optional nature are provided. These supplementary requirements call for
additional tests to be made, and when desired, shall be so stated in the order together with the number of such tests required.
1.4 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units
are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used
independently of the other. Combining values from the two systems may result in nonconformance with the specification. The
inch-pound units shall apply unless the “M” designation of this specification is specified in the order.
NOTE 2—The dimensionless designator NPS (nominal pipe size) has been substituted in this standard for such traditional terms as “nominal diameter,”
“size,” and “nominal size.”

2. Referenced Documents
2.1 ASTM Standards:
A 450/A 450M Specification for General Requirements for Carbon, Ferritic Alloy, and Austenitic Alloy Steel Tubes3
A 999/A 999M Specification for General Requirements for Alloy and Stainless Steel Pipe3
E 213 Practice for Ultrasonic Examination of Metal Pipe and Tubing4
E 309 Practice for Eddy-Current Examination of Steel Tubular Products Using Magnetic Saturation4
E 381 Method of Macroetch Testing Steel Bars, Billets, Blooms, and Forgings5
E 527 Practice for Numbering Metals and Alloys (UNS)3
E 570 Practice for Flux Leakage Examination of Ferromagnetic Steel Tubular Products4
2.2 Other Documents:
SNT-TC-1A Recommended Practice for Nondestructive Personnel Qualification and Certification6
SAE J 1086 Practice for Numbering Metals and Alloys (UNS)7
3. Ordering Information
3.1 Orders for material under this specification should include the following, as required, to describe the desired material
adequately:
3.1.1 Quantity (feet, centimetres, metres, or number of lengths),

3.1.2 Name of material (seamless alloy steel pipe),
3.1.3 Grade (Table 1),
3.1.4 Manufacture (hot-finished or cold-drawn),
3.1.5 Size using one of the following:
3.1.5.1 NPS and schedule number,
3.1.5.2 Outside diameter and nominal wall thickness,
3.1.5.3 Outside diameter and minimum wall thickness,
3.1.5.4 Inside diameter and nominal wall thickness, and
3.1.5.5 Inside diameter and minimum wall thickness.
3.1.6 Length (specific or random),
3.1.7 End finish (Ends Section of Specification A 999/A 999M),
3.1.8 Optional requirements (Section 8, 11 and 12 of this specification. See the Sections on Hydrostatic Test Requirements and
Permissible Variation in Weight for Seamless Pipe in Specification A 999/A 999M),
3.1.9 Test report required (Certification Section of Specification A 999/A 999M),
3.1.10 Specification designation, and
3.1.11 Special requirements or any supplementary requirements selected, or both.
4. General Requirements
4.1 Material furnished to this specification shall conform to the applicable requirements of the current edition of Specification
2

For ASME Boiler and Pressure Vessel Code applications see related Specification SA-335 in Section II of that Code.
Annual Book of ASTM Standards, Vol 01.01.
4
Annual Book of ASTM Standards, Vol 03.03.
5
Annual Book of ASTM Standards, Vol 03.01.
6
Available from the American Society for Nondestructive Testing, 1711 Arlingate Plaza, PO Box 28518, Columbus, OH 43228-0518.
7
Available from Society of Automotive Engineers, 400 Commonwealth Drive, Warrendale, PA 15096.

3

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A 335/A 335M – 023
TABLE 1 Chemical Requirements

Grade

UNS
DesignationA

Composition, %
Carbon

Manganese

Phosphorus,
max

Sulfur,
max

Silicon

Chromium

Molybdenum

P1
P2
P5
P5b
P5c
P9
P11
P12
P15
P21
P22
P23

K11522
K11547
K41545
K51545
K41245
S50400
K11597
K11562
K11578
K31545
K21590
K41650

0.10–0.20
0.10–0.20
0.15 max
0.15 max

0.12 max
0.15 max
0.05–0.15
0.05–0.15
0.05–0.15
0.05–0.15
0.05–0.15
0.04–0.10

0.30–0.80
0.30–0.61
0.30–0.60
0.30–0.60
0.30–0.60
0.30–0.60
0.30–0.60
0.30–0.61
0.30–0.60
0.30–0.60
0.30–0.60
0.10–0.60

0.025
0.025
0.025
0.025
0.025
0.025
0.025
0.025

0.025
0.025
0.025
0.030 max

0.025
0.025
0.025
0.025
0.025
0.025
0.025
0.025
0.025
0.025
0.025
0.010 max

0.10–0.50
0.10–0.30
0.50 max
1.00–2.00
0.50 max
0.25–1.00
0.50–1.00
0.50 max
1.15–1.65
0.50 max
0.50 max
0.50 max

...
0.50–0.81
4.00–6.00
4.00–6.00
4.00–6.00
8.00–10.00
1.00–1.50
0.80–1.25
...
2.65–3.35
1.90–2.60
1.90–2.60

0.44–0.65
0.44–0.65
0.45–0.65
0.45–0.65
0.45–0.65
0.90–1.10
0.44–0.65
0.44–0.65
0.44–0.65
0.80–1.06
0.87–1.13
0.05–0.30

P91

K91560

0.08–0.12

0.30–0.60

0.020

0.010

0.20–0.50

8.00–9.50

0.85–1.05

P92

K92460

0.07–0.13

0.30–0.60

0.020

0.010

0.50 max

8.50–9.50

0.30–0.60

P122

K92930

0.07–0.14

0.70 max

0.020

0.010

0.50 max

10.00–12.50

0.25–0.60

P911

K91061

0.09–0.13

0.30–0.60

0.020 max

0.010 max

0.10–0.50

8.50–10.50

0.90–1.10

Others
...
...
...
...
. . .B
...
...
...
...
...
...
V 0.20–0.30
Cb 0.02–0.08
B 0.0005–0.006
N 0.030 max
Al 0.030 max
W 1.45–1.75
V 0.18–0.25
N 0.030–0.070
Ni 0.40 max

Al 0.04 max
Cb 0.06–0.10
V 0.15–0.25
N 0.03–0.07
Ni 0.40 max
Al 0.04 max
Cb 0.04–0.09
W 1.5–2.00
B 0.001–0.006
V 0.15–0.30
W 1.50–2.50
Cu 0.30–1.70
Cb 0.04–0.10
B 0.0005–0.005
N 0.040–0.100
Ni 0.50 max
Al 0.040 max
V 0.18–0.25
Ni 0.40 max
Cb 0.060–0.10
B 0.0003–0.006
N 0.04–0.09
Al 0.04 max
W 0.90–1.10

A

New designation established in accordance with Practice E 527 and SAE J1086, Practice for Numbering Metals and Alloys (UNS).
Grade P 5c shall have a titanium content of not less than 4 times the carbon content and not more than 0.70 %; or a columbium content of 8 to 10 times the carbon
content.

B

A 999/A 999M, unless otherwise provided herein.
5. Materials and Manufacture
5.1 Pipe may be either hot finished or cold drawn with the finishing treatment as required in 5.3.
5.2 Grade P2 and P12—The steel shall be made by coarse-grain melting practice. Specific limits, if any, on grain size or
deoxidation practice shall be a matter of agreement between the manufacturer and purchaser.
5.3 Heat Treatment:
5.3.1 All pipe of grades shown in Table 1 except P5c, P23 P91, P92, P122, and P911 as provided in 5.3.2, shall be reheated
and furnished in the full-annealed, isothermal annealed, or normalized and tempered condition. If furnished in the normalized and
tempered condition, the minimum tempering temperature for Grades P5, P5b, P9, P21, and P22 shall be 1250°F [675°C], the
minimum tempering temperature for Grades P1, P2, P11, P12, and P 15 shall be 1200°F [650°C].
NOTE 3—It is recommended that the temperature for tempering should be at least 100°F [50°C] above the intended service temperature; consequently,
the purchaser should advise the manufacturer if the service temperature is to be over 1100°F [600°C].

5.3.2 Pipe of Grades P1, P2, and P12, either hot finished or cold drawn, may be given a final heat treatment at 1200°F [650°C]
to 1300°F [705°C] instead of heat treatments specified in 5.3.1.
5.3.3 All pipe of Grades P5c shall be given a final heat treatment in the range from 1325°F [715°C] to 1375°F [745°C].
NOTE 4—Certain of the ferritic steels covered by this specification will harden if cooled rapidly from above their critical temperature. Some will air

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A 335/A 335M – 023
harden, that is, become hardened to an undesirable degree when cooled in air from high temperatures. Therefore, operations involving heating such steels
above their critical temperatures, such as welding, flanging, and hot bending, should be followed by suitable heat treatment.

5.3.4 Grades P92 and P911 shall be normalized at 1900°F [1040°C] minimum and tempered at 1350°F [730°C] minimum as
a final heat treatment.
5.3.5 Grade P122 shall be normalized at 1900°F [1040°C] minimum, and tempered at 1350°F [730°C] minimum as a final heat

treatment.
5.3.6 Grade P23 shall be normalized at 1900°F [1040°C] minimum with air cooling or accelerated cooling and tempered at
1350°F [730°C] minimum as a final heat treatment.
5.4 Except when Supplementary Requirement S7 is specified by the purchaser, Grade P91 shall be normalized at 1900°F
[1040°C] minimum, and tempered at 1350°F [730°C] minimum as a final heat treatment. Alternatively, liquid quenching and
tempering is allowed for thicknesses above 3 in. when mutually agreed upon between the manufacturer and the purchaser. In this
case the pipe shall be quenched from 1900°F [1040°C] minimum and tempered at 1350°F [730°C] minimum as final heat
treatment.
6. Chemical Composition
6.1 The steel shall conform to the requirements as to chemical composition prescribed in Table 1.
7. Workmanship, Finish, and Appearance
7.1 The pipe manufacturer shall explore a sufficient number of visual surface imperfections to provide reasonable assurance that
they have been properly evaluated with respect to depth. Exploration of all surface imperfections is not required but may be
necessary to ensure compliance with 7.2
7.2 Surface imperfections that penetrate more than 121⁄2 % of the nominal wall thickness or encroach on the minimum wall
thickness shall be considered defects. Pipe with such defects shall be given one of the following dispositions:
7.2.1 The defect may be removed by grinding provided that the remaining wall thickness is within specified limits.
7.2.2 Repaired in accordance with the repair welding provisions of 7.6.
7.2.3 The section of pipe containing the defect may be cut off within the limits of requirements on length.
7.2.4 Rejected.
7.3 To provide a workmanlike finish and basis for evaluating conformance with 7.2, the pipe manufacturer shall remove by
grinding the following:
7.3.1 Mechanical marks, abrasions (see Note 5) and pits, any of which imperfections are deeper than 1⁄16 in. [1.6 mm].
NOTE 5—Marks and abrasions are defined as cable marks, dinges, guide marks, roll marks, ball scratches, scores, die marks, and the like.

7.3.2 Visual imperfections, commonly referred to as scabs, seams, laps, tears, or slivers, found by exploration in accordance
with 7.1 to be deeper than 5 % of the nominal wall thickness.
7.4 At the purchaser’s discretion, pipe shall be subject to rejection if surface imperfections acceptable under 7.2 are not
scattered, but appear over a large area in excess of what is considered a workmanlike finish. Disposition of such pipe shall be a
matter of agreement between the manufacturer and the purchaser.

7.5 When imperfections or defects are removed by grinding, a smooth curved surface shall be maintained, and the wall thickness
shall not be decreased below that permitted by this specification. The outside diameter at the point of grinding may be reduced
by the amount so removed.
7.5.1 Wall thickness measurements shall be made with a mechanical caliper or with a properly calibrated nondestructive testing
device of appropriate accuracy. In case of dispute, the measurement determined by use of the mechanical caliper shall govern.
7.6 Weld repair shall be permitted only subject to the approval of the purchaser and in accordance with Specification
A 999/A 999M.
7.7 The finished pipe shall be reasonably straight.
8. Product Analysis
8.1 At the request of the purchaser, an analysis of two pipes from each lot shall be made by the manufacturer. A lot (see Note
6) of pipe shall consist of the following:
NPS Designator
Under 2
2 to 5
6 and over

400 or fraction thereof
200 or fraction thereof
100 or fraction thereof

NOTE 6—A lot shall consist of the number of lengths specified in 8.1 of the same size and wall thickness from any one heat of steel.

8.2 The results of these analyses shall be reported to the purchaser or the purchaser’s representative, and shall conform to the
requirements specified in Table 1.
8.3 For grade P 91 the carbon content may vary for the product analysis by −0.01 % and +0.02 % from the specified range as
per Table 1.
8.4 If the analysis of one of the tests specified in 8.1 does not conform to the requirements specified in 6.1, an analysis of each
billet or pipe from the same heat or lot may be made, and all billets or pipe conforming to the requirements shall be accepted.
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A 335/A 335M – 023
9. Tensile and Hardness Requirements
9.1 The tensile properties of the material shall conform to the requirements prescribed in Table 2.
9.2 Table 3 lists elongation requirements.
9.3 Pipe of Grades P91, P92, and P122 shall have a hardness not exceeding 250 HB/265 HV [25 HRC].
9.4 Table 4 gives the computed minimum elongation values for each 1⁄32-in. [0.8-mm] decrease in wall thickness. Where the wall
thickness lies between two values above, the minimum elongation value is determined by the following formula:
Direction of Test
Longitudinal, all grades except P23, P91,
P92, P122, and P911

EquationB
E = 48t + 15.00
[E = 1.87t + 15.00]

Transverse, all grades except P23, P91,
P92, P122, and P911

E = 32t + 10.00
[E = 1.25t + 10.00]

Longitudinal, P23, P91, P92, P122, and
P911
where:
E = elongation in 2 in. or 50 mm, %, and
t = actual thickness of specimens, in. [mm].

E = 32t + 10.00
[E = 1.25t + 10.00]

10. Permissible Variations in Diameter
10.1 For pipe ordered to NPS or outside diameter, variations in outside diameter shall not exceed those specified in Table 5.
10.2 For pipe ordered to inside diameter, the inside diameter shall not vary more than 6 1 % from the specified inside diameter.
11. Hydrostatic Test
11.1 Each length of pipe shall be subjected to the hydrostatic test, except as provided for in 11.2 or 11.3.
11.2 Unless otherwise specified in the purchase order, each length of pipe shall, at the option of the manufacturer, be subjected
to the nondestructive electric test as shown in Section 12 in lieu of the hydrostatic test.
11.3 When specified by the purchaser, pipe shall be furnished without hydrostatic test and without nondestructive examination.
11.4 When specified by the purchaser, pipe shall be furnished with both the hydrostatic test and a nondestructive examination
having been performed.
12. Nondestructive Examination
12.1 When selected by the manufacturer or when specified in the order, as an alternative to the hydrostatic test (11.2), or when
secified in the purchase order in addition to the hydrostatic test (11.4), each pipe shall be examined by a nondestructive examination
method in accordance with Practice E 213, Practice E 309 or Practice E 570. The range of pipe sizes that may be examined by each
method shall be subject to the limitations in the scope of the respective practices.
12.2 The following information is for the benefit of the user of this specification:
12.2.1 The reference standards defined in 12.8 are convenient standards for standardization of nondestructive examination
equipment. The dimensions of these standards should not be construed as the minimum size imperfection detectable by such
equipment.
12.2.2 Ultrasonic examination can be performed to detect both longitudinally and transversely oriented discontinuities. It should
be recognized that different techniques should be employed to detect differently oriented imperfections. The examination may not
detect short, deep imperfections.
12.2.3 The eddy current examination referenced in this specification has the capability to detect significant discontinuities,
especially of the short abrupt type.
12.2.4 The flux leakage examination referred to in this specification is capable of detecting the presence and location of
significant longitudinally or transversely oriented discontinuities. It should be recognized that different techniques should be
employed to detect differently oriented imperfections.
12.2.5 The hydrostatic test of Section 11 has the capability to find imperfections of a size that permit the test fluid to leak
through the pipe wall so that it may be either visually seen or detected by a loss of fluid pressure. This test may not detect very

tight, through-wall imperfections, or imperfections that extend into the wall without complete penetration.
TABLE 2 Tensile Requirements
Grade
Identification Symbol
Tensile strength, min:
ksi
MPa
Yield strength, min:
ksi
MPa

P1, P2

P12

P23

P91

P92, P911

P122

All Others

55
380

60
415

74
510

85
585

90
620

90
620

60
415

30
205

32
220

58
400

60
415

64
440

58
400

30
205

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A 335/A 335M – 023
TABLE 3 Elongation Requirements
Elongation Requirements
All grades
except P23,
P91, P92, P122,
and P911

Elongation in 2 in. or 50 mm,
(or 4D), min, %:
Basic minimum elongation
for wall 5⁄16in. [8 mm] and
over in thickness, strip tests,
and for all small sizes tested
in full section
When standard round 2-in.
or 50-mm gage length or
proportionally smaller size
specimen with the gage
length equal to 4D (4 times

the diameter) is used
For strip tests a deduction
for each 1⁄32-in. [0.8 mm]
decrease in wall thickness
below in. [8 mm] from the
basic minimum elongation of
the following percentage
points shall be made
A

GAll other grades
P23, P91, P92,
P122, and P911

Longitudinal

Transverse

Longitudinal

Transverse

30

20

20

...

22

14

20

13

1.50A

1.00A

1.00A

...

Table 4 gives the calculated minimum values.

TABLE 4 Calculated Minimum Elongation Values
Elongation in 2 in. or 50 mm, min, %
Wall Thickness

in.
⁄ (0.312)
⁄ (0.312)
9⁄32 (0.281)
9⁄32 (0.281)
1⁄4 (0.250)
1⁄4 (0.250)
7⁄32(0.219)

3⁄16 (0.188)
5⁄32 (0.156)
1⁄8 (0.125)
3⁄32 (0.094)
1⁄16 (0.062)
5 16
5 16

All grades except P23, P91,
P92, P122, and P911

GAll
other
grades P23,
P91, P92, P122,
and P911

mm

Longitudinal

Transverse

Longitudinal

8
8
7.2
7.2
6.4

6.4
5.6
4.8
4
3.2
2.4
1.6

30
30
29
28
27
27
26
24
22
21
20
18

20.0
20
19.0
19
18.0
18
...
...
...

...
...
...

20
20
19
19
18
18
17
16
15
14
13
12

12.2.6 A purchaser interested in ascertaining the nature (type, size, location, and orientation) of discontinuities that can be
detected in the specific application of these examinations should discuss this with the manufacturer of the tubular products.
12.3 Time of Examination:
Nondestructive examination for specification acceptance shall be performed after all mechanical processing, heat treatments and
straightening operations. This requirement does not preclude additional testing at earlier stages in the processing.
12.4 Surface Conditions:
12.4.1 All surfaces shall be clean and free of scale, dirt, grease, paint, or other foreign material that could interfere with
interpretation of test results. The methods used for cleaning and preparing the surfaces for examination shall not be detrimental
to the base metal or the surface finish.
12.4.2 Excessive surface roughness or deep scratches can produce signals that interfere with the test (see 12.10.2.3).
12.5 Extent of Examination:
12.5.1 The relative motion of the pipe and the transducer(s), coil(s), or sensor(s) shall be such that the entire pipe surface is
scanned, except for end effects as noted in 12.5.2.

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A 335/A 335M – 023
TABLE 5 Permissible Variations in Outside Diameter
NPS Designator

Over

NPS Designator
⁄ to 11⁄2, incl.
Over 11⁄2 to 4, incl.
Over 4 to 8, incl.
Over 8 to 12, incl.
Over 12
18

Under
mm

in.
in.

in.

mm

⁄ (0.015)
1⁄32 (0.031)
1⁄16 (0.062)

3⁄32 (0.093)
6 1 % of the
specified
outside
diameter
1 64

0.40
0.79
1.59
2.38

in.
⁄
1⁄32
1⁄32
1⁄32
1 64

(0.015)
(0.031)
(0.031)
(0.031)

mm
mm
0.40
0.79
0.79
0.79

12.5.2 The existence of end effects is recognized, and the extent of such effects shall be determined by the manufacturer, and,
if requested, shall be reported to the purchaser. Other nondestructive tests may be applied to the end areas, subject to agreement
between the purchaser and the manufacturer.
12.6 Operator Qualifications—The test unit operator shall be certified in accordance with SNT-TC-1A, or an equivalent,
recognized and documented standard.
12.7 Test Conditions:
12.7.1 For examination by the ultrasonic method, the minimum nominal transducer frequency shall be 2.25 MHz.
12.7.2 For eddy current testing, the excitation coil frequency shall be 10 kHz, or less.
12.8 Reference Standards:
12.8.1 Reference standards of convenient length shall be prepared from a length of pipe of the same grade, size (NPS or outside
diameter and schedule or wall thickness), surface finish and heat treatment condition as the pipe to be examined.
12.8.2 For ultrasonic testing, the reference notches shall be any one of the three common notch shapes shown in Practice E 213,
at the option of the manufacturer. The depth of the notch shall not exceed 121⁄2 % of the specified nominal wall thickness of the
pipe or 0.004 in. (0.1 mm), whichever is greater. The length of the notch shall be at least twice the diameter of the transducer(s).
The width of the notch shall not exceed the depth.
12.8.3 For eddy current testing, the reference standard shall contain, at the option of the manufacturer, any one of the following
discontinuities:
12.8.3.1 Drilled Hole—The reference standard shall contain three or more holes, equally spaced circumferentially around the
pipe and longitudinally separated by a sufficient distance to allow distinct identification of the signal from each hole. The holes
shall be drilled radially and completely through the pipe wall, with care being taken to avoid distortion of the pipe while drilling.
The hole diameter shall vary with NPS as follows:
NPS Designator
1⁄2
above 1⁄2 to 11⁄4
above 11⁄4to 2
above 2 to 5
above 5

Hole Diameter

0.039 in. (1 mm)
0.055 in. (1.4 mm)
0.071 in. (1.8 mm)
0.087 in. (2.2 mm)
0.106 in. (2.7 mm)

12.8.3.2 Transverse Tangential Notch—Using a round tool or file with a 1⁄4 in. (6.4 mm) diameter, a notch shall be filed or milled
tangential to the surface and transverse to the longitudinal axis of the pipe. Said notch shall have a depth not exceeding 121⁄2 %
of the specified nominal wall thickness of the pipe or 0.004 in. (0.1 mm), whichever is greater.
12.8.3.3 Longitudinal Notch—A notch 0.031 in. or less in width shall be machined in a radial plane parallel to the tube axis on
the outside surface of the pipe, to have a depth not exceeding 121⁄2 % of the specified nominal wall thickness of the pipe or 0.004
in. (0.1 mm), whichever is greater. The length of the notch shall be compatible with the testing method.
12.8.4 For flux leakage testing, the longitudinal reference notches shall be straight-sided notches machined in a radial plane
parallel to the pipe axis. For wall thickness less than 1⁄2 in. (12.7 mm), outside and inside notches shall be used; for wall thicknesses
equal to or greater than 1⁄2 in., only an outside notch shall be used. Notch depth shall not exceed 121⁄2 % of the specified nominal
wall thickness or 0.004 in. (0.1 mm), whichever is greater. Notch length shall not exceed 1 in. (25.4 mm), and the width shall not
exceed the depth. Outside and inside notches shall have sufficient separation to allow distinct identification of the signal from each
notch.
12.8.5 More or smaller reference discontinuities, or both, may be used by agreement between the purchaser and the
manufacturer.
12.9 Standardization Procedure:
12.9.1 The test apparatus shall be standardized at the beginning and end of each series of pipes of the same size (NPS or
diameter and schedule or wall thickness), grade and heat treatment condition, and at intervals not exceeding 4 h during the
examination of such pipe. More frequent standardizations may be performed at the manufacturer’s option or may be required upon
agreement between the purchaser and the manufacturer.
12.9.2 The test apparatus shall also be standardized after any change in test system settings, change of operator, equipment
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A 335/A 335M – 023

repair, or interruption due to power loss, shutdown or operator breaks.
12.9.3 The reference standard shall be passed through the test apparatus at same speed and test system settings as the pipe to
be tested.
12.9.4 The signal-to-noise ratio for the reference standard shall be 2.5 to 1 or greater and the reference signal amplitude for each
discontinuity shall be at least 50 % of full scale of the display.
12.9.5 If upon any standardization, the reference signal amplitude has decreased by 25 % (2 db), the test apparatus shall be
considered out of standardization. The test system settings may be changed, or the transducer(s), coil(s) or sensor(s) adjusted, and
the unit restandardized, but all pipe tested since the last acceptable standardization must be retested.
12.10 Evaluation of Imperfections:
12.10.1 Pipes producing a signal equal to or greater than the signal produced by the reference standard shall be positively
identified and they shall be separated from the acceptable pipes. The area producing the signal may be reexamined.
12.10.2 Such pipes shall be subject to one of the following three dispositions:
12.10.2.1 The pipes may be rejected without further examination, at the discretion of the manufacturer.
12.10.2.2 The pipes shall be rejected, but may be repaired, if the test signal was produced by imperfections which cannot be
identified, or was produced by cracks or crack-like imperfections. These pipes may be repaired by grinding (in accordance with
7.2.1), welding (in accordance with 7.6) or sectioning (in accordance with 7.2.3). To be accepted, a repaired pipe must pass the
same nondestructive examination by which it was rejected, and it must meet the remaining wall thickness requirements of this
specification.
12.10.2.3 Such pipes may be evaluated in accordance with the provisions of Section 7, if the test signals were produced by
visual imperfections such as those listed below:
(a) Scratches,
(b) Surface roughness,
(c) Dings,
(d) Straightener marks,
(e) Cutting chips,
(f) Steel die stamps,
(g) Stop marks, or
(h) Pipe reducer ripple.
13. Mechanical Tests Required
13.1 Transverse or Longitudinal Tension Test and Flattening Test, Hardness Test, or Bend Test—For material heat treated in a

batch-type furnace, tests shall be made on 5 % of the pipe from each treated lot (see Note 7). For small lots, at least 1 pipe shall
be tested. For material heat treated by the continuous process, tests shall be made on a sufficient number of pipe to constitute 5 %
of the lot (see Note 7), but in no case less than 2 pipe.
NOTE 7—The term “lot” applies to all pipe of the same nominal size and wall thickness (or schedule) which is produced from the same heat of steel
and subjected to the same finishing treatment in a continuous furnace; when final heat treatment is in a batch-type furnace, the lot shall include only that
pipe which is heat treated in the same furnace charge.

13.2 Hardness Test:
13.2.1 For pipe of Grades P91, P92, P122, and P911, Brinell, Vickers, or Rockwell hardness tests shall be made on a specimen
from each lot (see Note 7).
13.3 Bend Test:
13.3.1 For pipe whose diameter exceeds NPS 25 and whose diameter to wall thickness ratio is 7.0 or less shall be subjected to
the bend test instead of the flattening test. Other pipe whose diameter equals or exceeds NPS 10 may be given the bend test in place
of the flattening test subject to the approval of the purchaser.
13.3.2 The bend test specimens shall be bent at room temperature through 180° without cracking on the outside of the bent
portion. The inside diameter of the bend shall be 1 in. [25 mm].
13.3.3 Test specimens for the bend test specified in 13.3 shall be cut from one end of the pipe and, unless otherwise specified,
shall be taken in a transverse direction. One test specimen shall be taken as close to the outer surface as possible and another from
as close to the inner surface as possible. The specimens shall be either 1⁄2 by 1⁄2 in. [12.5 by 12.5 mm] in section or 1 by 1⁄2 in.
[25 by 12.5 mm] in section with the corners rounded to a radius not over 1⁄16 in. [1.6 mm] and need not exceed 6 in. [150 mm]
in length. The side of the samples placed in tension during the bend shall be the side closest to the inner and outer surface of the
pipe, respectively.
14. Certification
14.1 In addition to the information required by Specification A 999/A 999M, the certification shall state whether or not the
material pipe was hydrostatically tested. If the material pipe was nondestructively examined, the certification shall so state and
shall show which practice was followed and what reference discontinuities were used. In addition, the test method information as
given in Table 3 6 shall be appended to the specification number and grade shown on the certification.
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A 335/A 335M – 023
TABLE 6 Test Method Information for Certification and Marking
Hydrostatic

Nondestructive

Marking

YES
NO
NO
YES

NO
YES
NO
YES

Test Pressure
NDE
NH
Test Pressure/NDE

15. Product Marking
15.1 In addition to the marking prescribed in Specification A 999/A 999M, the marking shall include the length, an additional
symbol “S”, if the pipe conforms to any of the Supplementary Requirements S1 to S6, the ANSI schedule number, if the pipe is
ordered to a schedule number, and the heat number or manufacturer’s number by which the heat can be identified. Furthermore,
the marking designated in Table 6 to indicate the test method(s) shall be included. Marking may be by stenciling, stamping, or
rolling. Pipe that has been weld repaired in accordance with 7.6 shall be marked “WR.”
16. Government Procurement

16.1 Scale Free Pipe:
16.1.1 When specified in the contract or order, the following requirements shall be considered in the inquiry contract or order,
for agencies of the U.S. Government where scale free pipe or tube is required. These requirements shall take precedence if there
is a conflict between these requirements and the product specification.
16.1.2 The requirements of Specification A 999/A 999M for pipe and Specification A 450/A 450M for tubes shall be applicable
when pipe or tube is ordered to this specification.
16.1.3 Pipe and tube shall be one of the following grades as specified herein:
Grade
P11
P22
P5

UNS Designation
K11597
K21590
K41545

16.1.4 Part Number:
16.1.4.1 Pipe shall be ordered to nominal pipe size and schedule specified in ANSI B36.10
Example: A 335/A 335M Pipe P-11 NPS 12 Sch 40
Specification Number
Pipe
Grade
NPS
Wall

ASTM A 335/A 335M
P
P-11
12

0.375

Specification Number
Tube
Grade
Ouside Diameter
Wall

ASTM A 335/A 335 M
T
P-11
0.250
0.035

16.1.4.2

16.1.5 Ordering Information—Orders for material under this specification shall include the following in addition to the
requirements of Section 4: 3:
16.1.5.1 Pipe or tube,
16.1.5.2 Part number,
16.1.5.3 Ultrasonic inspection, if required,
16.1.5.4 If shear wave test is to be conducted in two opposite circumferential directions, and
16.1.5.5 Level of preservation and packing required.
17. Keywords
17.1 alloy steel pipe; high temperature service; seamless steel pipe; steel pipe; temperature service applications; high
applications

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A 335/A 335M – 023
SUPPLEMENTARY REQUIREMENTS
One or more of the following supplementary requirements shall apply only when specified in the
purchase order. The purchaser may specify a different frequency of test or analysis than is provided
in the supplementary requirement. Subject to agreement between the purchaser and manufacturer,
retest and retreatment provisions of these supplementary requirements may also be modified.
S1. Product Analysis
S1.1 Product analysis shall be made on each length of pipe. Individual lengths failing to conform to the chemical composition
requirements shall be rejected.
S2. Transverse Tension Tests
S2.1 A transverse tension test shall be made on a specimen from one end or both ends of each pipe NPS 8 and over. If this
supplementary requirement is specified, the number of tests per pipe shall also be specified. If a specimen from any length fails
to meet the required tensile properties (tensile, yield, and elongation), that length shall be rejected subject to retreatment in
accordance with Specification A 999/A 999M and satisfactory retest.
S3. Flattening Test
S3.1 The flattening test of Specification A 999/A 999M shall be made on a specimen from one end or both ends of each pipe.
Crop ends may be used. If this supplementary requirement is specified, the number of tests per pipe shall also be specified. If a
specimen from any length fails because of lack of ductility prior to satisfactory completion of the first step of the flattening test
requirement, that pipe shall be rejected subject to retreatment in accordance with Specification A 999/A 999M and satisfactory
retest. If a specimen from any length of pipe fails because of a lack of soundness that length shall be rejected, unless subsequent
retesting indicates that the remaining length is sound. The bend test of 13.2 shall be substituted for the flattening test for pipe whose
diameter exceeds NPS 25 and whose diameter to wall thickness ratio is 7.0 or less.
S4. Metal Structure and Etching Tests
S4.1 The steel shall be homogeneous as shown by etching tests conducted in accordance with the appropriate portions of
Method E 381. Etching tests shall be made on a cross section from one end or both ends of each pipe and shall show sound and
reasonably uniform material free from injurious laminations, cracks, and similar objectionable defects. If this supplementary
requirement is specified, the number of tests per pipe required shall also be specified. If a specimen from any length shows
objectionable defects, the length shall be rejected, subject to removal of the defective end and subsequent retests indicating the
remainder of the length to be sound and reasonably uniform material.
NOTE S4.1—Pending development of etching methods applicable to the product covered by this specification, it is recommended that the

Recommended Practice for a Standard Macro Etch Test for Routine Inspection of Iron and Steel, described in the Metals Handbook, Am. Soc. for Metals,
1948 edition, p. 389, be followed.

S5. Photomicrographs
S5.1 When requested by the purchaser and so stated in the order, the manufacturer shall furnish one photomicrograph at 100
diameters from a specimen of pipe in the as-finished condition for each individual size and wall thickness from each heat, for pipe
NPS 3 and over. Such photomicrographs shall be suitably identified as to pipe size, wall thickness, and heat. No photomicrographs
for the individual pieces purchased shall be required except as specified in Supplementary Requirement S6. Such photomicrographs are for information only, to show the actual metal structure of the pipe as finished.
S6. Photomicrographs for Individual Pieces
S6.1 In addition to the photomicrographs required in accordance with Supplementary Requirement S5, the purchaser may
specify that photomicrographs shall be furnished from each end of one or more pipes from each lot of pipe NPS 3 and larger in
the as-finished condition. The purchaser shall state in the order the number of pipes to be tested from each lot. When
photomicrographs are required on each length, the photomicrographs from each lot of pipe in the as-finished condition which may
be required under Supplementary Requirement S5 may be omitted. All photo-micrographs required shall be properly identified as
to heat number, size, and wall thickness of pipe from which the section was taken. Photomicrographs shall be further identified
to permit association of each photomicrograph with the individual length of pipe it represents.
S7. Alternative Heat Treatment—Grade P91
S7.1 Grade P91shall be normalized in accordance with 5.3 and tempered at a temperature, to be specified by the purchaser, less
than 1350°F [730°C]. It shall be purchaser’s responsibility to subsequently temper at 1350°F [730°] minimum. All mechanical tests
shall be made on material heat treated in accordance with 5.3. The certification shall reference this supplementary requirement
indicating the tempering temperature applied. The notation “S7’’ shall be included with the required marking of the pipe.
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A 335/A 335M – 023
SUMMARY OF CHANGES
This section identifies
Committee A01 has identified the principal location of selected changes to this specification standard since the
last edition (A 335/A 335M-02) that may impact the use of this standard (approved April 2003).
(1) Changed “centimetres” to “metres” in 3.1.1.

(2) Added grade and format changes to Table 2.
(3) Added format changes to Table 3.
(4) Added format changes and rounded values in Table 4.
(5) Added format changes to Table 5.
(6) Replaced “material” with “pipe” in 14.1, and changed reference to Table 3 in 14.1 to Table 6.
(7) Deleted “ANSI” from 15.1 and added new text.
(8) Deleted “tube” throughout Section 16.
(9) Changed reference from Section 4 to Section 3 in 16.1.5.
(10) Deleted the word “high” from the Keywords section.

Committee A01 has identified the location of selected changes to this standard since the last edition (A 335/A 335M – 01) that
may impact the use of this standard (approved Spetember 2002).
(1) Revised paragraphs 9.3, 9.4, and 13.2.1.
(2) Revised Table 3, Table 4, and Table 5.
(3) Revised paragraphs 1.1, 3.1.5, and 10.1.
(4) Added new paragraph 10.2.
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